Safety-guard for punch-presses



A. KOETTING.

SAFETY GUARD FOR PUNCH PRESSES.

APPLICATION FILED OCT. I, I9I9. Patented July 13,1920.

3 SHEETS-SHEET I.

WITNESSES i A j llvl Em og ATTORNEYS A. KOETTING.

SAFETY GUARD FOR PUNCH PRESSES..

Patehted July 13, 1920.

3 SHEEN-SHEET 2.

APPLICATION FILED OCT. 1. l9l9.

llilll A TTORNEYS A. KOETTING.

SAFETY GUARD FOR PUNCHH'PRESSES.

APPLICATION men OCT. 1. 1919.

. 3 SHEElS-SHEET a,

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27 23 I v ATTORNEYS UNITED STATES PATENT I orF cs.

l AUGUST KOETTING, OF BROOKLYN, NEW YORK.

SAFETY-GUARD FOR PUNCH-PRESSES.

Specification of Letters Patent.

Patented July 13, 1920.

Application filed October 1, 1919. Serial No. 327,731.

To all whom it may concern.-

Be it known that I, AUGUST KOETTING, a

citizen of the United States, and a resident machinery such as metal punches, shears or the like, and has particular reference to safety appliances for such machines.

Among the objects of the invention is to provide an automatic guard or fender adapted to be brought successively into position to protect the operators hands from injury due to the descent of the power operated tool such as a punch, die, or the'like.

Another object of the invention is to provide a guard or fender of the nature indicated that will not only act promptly and reliably as a protector to the ,operators hands but which will not interfere with the normal intended operation of the machine upon the metal sheets 'or other commodity being treated upon or by the machine.

'With the foregoing and other objects in view the invention consists in the arrangement and combination of parts hereinafter described and claimed, andwhile the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which- Figure 1 is a side elevation, partly broken away, indicating a conventional type of power operated punch press with my improvement attached thereto in normal elevated position.

Fig. 2 is a horizontal section on the line 22 of Fig. 1.

Fig. 3 is a side elevation of the table portion of the press indicating the fender in its depressed position.

Fig. 4 is a front elevation of the fender at about the time it is brought into contact with the press table or at the stage of operation indicated in Fig. 6.

Fig. 5 is a side elevation of the main part of my improved attachment with the face plate removed to show the interior mechanism in normal idle position.

Fig. 6 is a similar View indicating the I same parts at the end of what would be termed the first stage of operation or first portion of the downward thrust ,of the treadle.

Flg. 7 is a view of the same parts at the t1me the downward stroke of the treadle is nearlng completion and about to release the clutch connector. 0

Flgs. 8 and 9 are horizontal sectional details on the corresponding lines of Fig. 5. Fig. 10 is a vertical sectional view on the 1 line 1010 of Fig. 5.

Fig. 11 is a rear perspective view of the knock-off abutment member.

Fig. 12 is a front perspective view of the pgvgted dog and the slide to which it is pivo e Referrin now more specifically to the draw1ngs show a power operated punch press having a base 15, a table 16, an upright frame 17, an operating shaft 18 and a treadle 19, all of which parts are or may be of any well known 'or conventional des1gu or construction.

. hereas in the usual practice the tool is operated periodically from and by the power shaft 18 as a result of a suitable clutch device 20 having direct connection with the treadle, in this instance the connection between the clutch and the treadle is effected indirectly through an automatic attachment 21 shown as located on the right side of the frame 17 but including parts as for example a shaft 22 extending across or journaled in the two side members of the frame.

The attachment is shown in the form of a casing of flat circular form, the body portion of which is fixed by any'suitable means rigidly to the adjacent side member of the frame 17 and having a removable face plate for affording access to the interiorof the casing. As indicated in the-detail views the shaft 22 is journaled in the lower right hand corner of the casing and fixed rigidly but adjustably to the shaft. Within the casing is an actuator arm 23 having at its front end a slotted head 24, the slot being slubs iantially concentric with the axis of the s a The casing 21 is fixed to the frame 17 preferably in spaced relation and located in the space between the casin and the frame is a lever 25 fixed to the s aft 22. The free end of the lever projects forward alon the frame toward or into the throat 26 o the machine andto which the treadle 19 connected by means of a rod 27 engagedm any one of a seiies of holes 28 formed 1n said lever, the point of connection belng determined by the required throw of the lever in the practice of any particular machlne. Obviously the depression of the treadle Wlll cause a partial rotation of the shaft 22 in the same direction and the movement of the actuator 23 from the normal position ofFig.

with a link 32 connected in turn at its upper end through a in and slot connection 33 with-the aforesald clutch 20. The slideway 29 is wide enough at its lower end to accommodate a slide 34 lying parallel to the lower end of the connector and having pivotally attached to its upper end at 35 a dog 36.

The dog lies normally in alinem'ent with the into the notch at the intended time.

slide 34 with its hook 36 engaged in a notch 30 of the connector, this position of the dog being established and maintained by means of a detent 37 pivoted at 38 in a recess 39 at the right of the dog and acted upon constantly by means of a spring 40 tending to force the detent against the dog and the gig e slide 34 has a laterally projecting pin 41 cooperating with the slotted end of the actuator 23. The dog 36 has a laterally projecting pin 42.

The fender above referred to is indicated at 43 and is carried by a pair'ofarms 44 fixed uponthe shaft '22 by means of clamps 45, or their equivalent, and preferably within the space between the side walls of the frame 17 These'arms' after projecting forward from the frame diverge from each other and thence extend, forward parallel again to their points of attachment 46 with the fender. Thisv gives ample room between the arms forl the operation of the tool and the placenter1 t of. any work to-be acted upon. WhenQthe-shaft 22 is given an oscillation downward as. a result .of the depression of the treadle 19 the fender is brought promptly downward to or toward the table 16 of the press. This movement of the fender is coincident with the depression of the treadle and reaches about the stage indicated in Fig.

4, in guarding position, by the time the'pin 41 is engaged by the upper part'of the end 24 of the actuator 23, as in Fig. 6. Conse quently the operators'hands must be out :of

the way by this time or else they will-so obstruct the movement of the fender as to prevent the operation of the clutch'20 which is effected when and only when the treadle is further depressed from the position corresponding to that of Fig. 6, that is to say if the operators hands or any other obstruction should be located at this time beneath the fender preventing further movement downward thereof, the slide 34 cannot be moved downward. The operator therefore will be duly apprisedof the circumstances l5 and will have ample time to remedy the condition. I p v I In the subsequent movement of the treadle downward, which as a matter of fact is in" effect the result of a continued movement of the foot, the slide 34 is actuated through the pin 41 and so the dog 36 is drawn downward bringing with it the connector 30 and resulting in the actuation of the clutch 20 and I operation of the machine for its intended purpose. Buffers 47 of any suitable nature carried by the fender provide for further depression of'the fender in accordance with the second stage of movement of the treadle. The position upon the table 16 of any long sheets or'strips of metal or the like to be acted upon will not prevent proper operation of the machine or the fender.

Any suitable means may be provided to knock-off the dog from the connector or 96 to sever the connection between these two members by the time the treadle has been given a full downward stroke by the operators foot. To this end I provide a member or keeper 48, see Fig. 11, in the nature of 100 a bar having vertically arranged slotted ends 49 whereby the keeper member is held in horizontal position at a proper level. As a keeper this member serves to hold the connector, dog, slide and detent in the slide- Way and recesses. The primary function, however, of this ,member is to detach the dog from the connector which is accomplished by reason of an inclined shoulder 50 formed on the rear surface of the bar and arranged in the vertical path of the pin 42. When the slide 34 and dog are drawn downward from the position of Fig. 6 to that of Fig. 7 the pin 42 strikes and wipes against the inclined shoulder 50 and thereby the dog is thrown to the right free from the notch 30 and against the force of the spring 40. The instant that the connector is thus released from the dog a spring 51 acts to throw it upward to normal posltion to disconnect the clutch 20 which by this time has been connected and has been functional to cause the operation of the machine as a result of the, downward movement of the connector from the position of Fig. 6. 126 The spring 51 is mounted upon a fixed guide pin 52 supported in the bottom of the easing 21 at the lower end of the slideway 29. A similar spring 53 similarly supported upon a fixed pin 54 acts upon the slide 34 130 to resiliently resist the downward movement thereof and to restore it to normal position for the rengagement of the dog with the connector as shown in Fig. 5. The position of the knock-off keeper 48. with respect to the height of the pin 42 is variable in various machines or in accordance with the time when the connector is to be released. This variation in vertical adjustment of the keeper may be effected in various ways through the clamping nuts 55 alone or in connection with a strut 56 having its lower headed end journaled in an abutment 57 across the lower end of the slideway 29 and having its upper threaded end tapped into and through an abutment 58 carried by the front face of the keeper. Lock nuts 59 may be employed on the upper and lower sides of this latter abutment, to hold the strut from rotation when the machine is in operation.

Any suitable counterbalancing means may be provided for the fender for the pur pose of facilitating the action thereof in making it more prompt and'reliable. To this end I provide a counter-weight 60 fixed adjustably upon an arm 61 clamped at 62 upon the middle portion of the shaft 22.

The mass or weight acts normally to lift or tend to lift the fender 43. In addition to the weight a counter-balancing spring 63 may be employed to expedite the movement of the fender upward. The connecting and disconnecting means between the treadle and the machine clutch is'so designed that it is practically impossible for the machine to make a second power stroke or reciprocation unless the treadle is released and the fender is permitter to make its intended oscillations. In other words the operator is required, after giving a full downwar stroke on the treadle, to release the treadle in order to again initiate the action of the punch or other tool for the reason that the connection between the treadle and the tool controlling means is automatically severed during the latter part of the down thrust of the treadle. Furthermore the fender is held down in guarding position as long as the treadle is held down.

I claim:

1. In a safety appliance for punch presses or the like, the combination with a treadle and means set into action by the depression of the treadle to initiate the action of the press, of a fender movable from idle into guarding position, and connections between the treadle and the fender to cause movement of the latter into arding position during the first portion 0 the movement of the treadle and prior to initiation of the movement of the press, said connections comprising a rock shaft, a pair of arms fixed to the rock shaft and extending forward parallel to each other and thence deflected laterally to each other, and clamping means between the forward ends of the arms and the fender.

2. In a safety appliance for punch presses, the combination of a fender movable from normal idle position into guarding position, a shaft upon which the fender is mounted, manually operated means to rotate the shaft to bring the fender into guarding position, and means to start the press during the continued movement of said manual means, the press starting means including a vertical slide and havinga laterally projecting finger, an actuator fixed to the shaft and having slotted eoiiperation with said finger providing for an initial movement of the fender preliminary to the initiation of the press movement, a vertical connector adjacent to the slide, and a dog pivoted to the upper end of the slide and having interlocking cooperation with the connector to draw the latter downward with the downward movement of the slide.

3. In a safety appliance for punch'presses, the combination of a fender, a shaft upon which the fender is mounted, manual means for turning the shaft to bring the fender into guarding position, automatic means acting to return the fender and shaft to normal position, and automatically disconnectible means to initiate the action of the press after the fender has been brought into guarding position and comprising vertically disposed parallel slide and connector members, a dog connected to the slide and having a hooked end eo5perating in a notch in the connector to draw the latter downward, said dog having a laterally projecting finger and a horizontal knock-off keeper serving to hold the slide and connector in proper position, and having an inclined shoulder on the side adjacent to the dog against which the dog and finger operates to release the dog from the connector when the slide is drawn downward, said press initiating means being automatically disconnected during the latter part of the movement of the manual means and prior to the return of the fender to its idle position.

AUGUST KOETTING. 

